Crystallographic, like all other formulæ, are simply short-hand methods of describing that which could otherwise only be rendered intelligible by the expenditure of many words, and, in type, by considerable waste of space. Anything, therefore, which tends to simplify and contract formulæ, without diminishing the amount of information which they convey, must necessarily be advantageous. The different systems of notation used at the present time by eminent crystallographers render the comprehension, of their formulæ somewhat difficult to the student; and it would doubtless be productive of much satisfaction if a universal system of crystallographic notation could be adopted.